Principles of wound healing

Question 1

What are the consequences of failure to manage wound correctly?

Answer 1

delayed healing
prolonged discomfort
extra costs

Question 2

What are the 3 healing phases?

Answer 2

1.Inflammatory phase
2.Proliferative phase
3.Remodelling phase

Question 3

what happens in the inflammatory phase?

Answer 3

1.tissue disruption initiates haemostasis and inflammation + vessels vasoconstrict
2.vasodilation after few minutes = heat,redness+swelling + fibrin seal created
3.platelets aggregate and release chemoattractants, growth factors + proteases = removal of wound contaminants and dead tissue
4.neutrophils arrive then macrophages - kill bacteria and debride wound

Question 4

What happens in the proliferative phase?

Answer 4

1. angiogenesis - microvascular network provide o2 and nutrients
2. fibroblasts start synthesis of collagen and also turn to myofibroblasts causing wound contraction + development of granulation tissue
   3.epithelial cells proliferate + recreate normal epidermal thickness.

Question 5

What happens in the remodelling phase?

Answer 5

1.Strengthening of collagen, increased stiffness of tissue
2. Collagen synthesis completed at 4-5 weeks
collagen maturation for 12-18months

Question 6

What are the local factors affecting wound healing? (5)

Answer 6

Wound perfusion
tissue viability
wound fluid accumulation
infection
mechanical factors (movement)

Question 7

What are the systemic factors affecting wound healing? (6)

Answer 7

immunology
oncology
systemic conditions
thermal injuries
external agents
excessive scarring

Question 8

What are the different open wounds? (8)

Answer 8

laceration
abrasion
surgical incision
degloving
puncture
shearing
burn
pressure sore

Question 9

What are the different closed wounds? (4)

Answer 9

contusion
haematoma
crush injury
hygroma

Question 10

What infection should always be checked for?

Answer 10

tetanus -fatal if not vaccinated or treated

Question 11

What are the requirements for primary closure?

Answer 11

1. minimal bacterial contamination
2. devitalised tissue, foreign bodies and blood clots removed
   3.no dead space, ischaemia, or haematomas

Question 12

What can be done for after care of surgical wounds?

Answer 12

use of antibiotics/NSAIDs
buster collar
rest
removal of skin sutures (10-14d after)
good hygiene and biosecurity